Good luck chap
Santaman, what would you attach to these, purely academic from my point of view but interesting none the less.
I'm not sure I understand your question Rik.
Are you asking about attaching the patrol pack? If so here is a link to it
www.nxsurplus.com/backpacks/cfp-90/the-cfp-90-patrol-pack It has a 1 inch webbing strap in each corner with fastex buckles to attach to the main pack near or on the top. When attached it adds to the total capacity of the system (an additional 1200 cubic inches or about 20 liters) When detached, the patrol pack has its own carry straps and is a two compartmant day pack. Disclaimer: The above link is likely a cheap, low quality commercial knock-off rather than a genuine pack at that price.
Or are you asking what you would attach to the large webbing sewn around the main pack? That was designed to attach any gear with ALICE clips too
www.redesupply.com/p596/ALICE-Clips/product_info.html They were use to attach any/everythingfrom compass pouches, 1st aid kits, canteens, etc. ALICE clips have been almost universally replaced by the MOLLE system in military usage but they are plentifully and cheaply available as surplus. The grommets you see in that webbing is spaced to accept the older wire hanger type attachments found on military gear. Those webbing points also work well with lashing straps.
Please understand that I'm still learning about this pack too. I remember lusting for it when it first appeared (in the early 1990s) but it was never in general issue and new ones were going fo over $200. It was meant as a replacement for the older ALICE packs, especially for extended or cold weather ops, but MOLLE soon took over the military market.